Flexible high frequency cable



Feb. 6, 1940.

F. uNTERBuscH 2,189,091

FLEXIBLE HIGH FREQUENCY CABLE Filed Nov. 7, 1936 Cop/D56 UNITED STATES PATENT OFFICE FLEXIBLE HIGH FREQUENCY CABLE Franz Unterbusch, Cologne-Mulheim, Germany, assigner to Felten & Guilleaume Carlswerk Actien-Gesellschaft, Cologne-Mulheim, Germany Application November 7, 1936, Serial No. 109,763 In Germany December 2, 1935 1 Claim. (Cl. 174-29) It is known in high frequency cables with a mechanical influences it may further be provided concentric arrangement of the conductors to obwith an armouring in a known manner. tain a high longitudinal conductivity by making One form of carrying the invention into eii'ect the concentric return conductor of iiat copper is illustrated, by way of example, in the accoml wires, or Wires of circular cross-section, which panying drawing, in which l is a metal strand, 2 5 are laid round the other insulated conductor. It a helix of insulating material, for instance has been found that such a return conductor polystyrol, which is formed of closely adjacent becomes contorted when the cable is twisted, helical turns and is placed around the strand l l namely, in such a way that individual wires are to serve as a distance holder. A band 3 is 1 buckled inwards, with the result that the insulaplaced on the helix 2, being wound thereon in 10 tion, which in the case of high frequency cables helical turns and leaving a free space between has to be built up as an air-space insulation, is the turns. This helical band 3 serves as a suppierced and may lead to a short circuit with the porting member for a wire braiding I, which is inner conductor. surrounded by a protective covering 5.

According to the invention the return conduc- What I claim is: 15 tor is made of a braiding of flat copper wires, or A flexible high frequency cable having an inner copper wires of circular cross-section and one or conductor, an outer tubular conductor concentric more helical bands of metal is or are provided therewith and consisting of a wire braiding, a under the tubular braiding for the purpose oi' solid insulating material applied in such a man- 20 resisting pressure. Such a cable has a greater ner as to provide a substantial airspace between exibility and, more particularly, the return conthe said two conductors and a metal band wound ductor is not sensitive with respect to twisting. in the form of an open helix between the said air- 'I'he inner conductor must also be flexible, and space insulation and the said outer tubular confor this reason it is preferably made of a. copper ductor of wire braiding, said helically wound strand. metal band supporting the wire braiding conz5 A protective covering of rubber or similar ilexductor. ible material is preferably provided over the outer conductor. In order to protect the cable against FRANZ UNTERBUSCH. 

